Acoustical control device



May 14, 1968 M. R. BIGGS ACOUSTICAL CONTROL DEVTCE Filed June 6, 1967.par

INVENTOR. /M/LLHD B/GGS United States Patent O 3,382,947 ACOUSTICALCONTROL DEVICE Miliard R. Biggs, 4911 Campanile Drive, San Diego, Caiif.92115 Filed .lune 6, 1967, Ser. No. 644,467

. 2 Claims. (Cl. 181-30) ABSTRACT F THE BISCLOSURE An acoustical controldevice comprising a plurality of triangular cylinders 4rotatably mountedin a parallel adjacent relationship where each triangular cylinder hasone. side with a sound reecting surface such as berboard, a second sidehaving a surface for medium sound absorptions such as acoustical tile,and a third surface having a high sound absorption such as fiberglassinsulation, each of said sections being individually rotatable for theexposure of any combination of these three surfaces as dictated by theacoustical parameters of its environment and the sound source exposedthereto.

Background of the invention The present invention relates to anacoustical control device and more particularly to an acoustical controldevice for optimizing the acoustics of a given invironment and soundsource.

The prior art acoustical control devices have at best resulted inextremely cumbersome and expensive attempts to vary the acoustics in agiven environment. Some of these implementations have resulted inextremely complex systems gearing various cylinders to expose differentsurfaces by exercising some acoustical control over a particularenvironment. The main disadvantages of the prior art devices have beenin their extreme complexity, resulting in high cost, and in their lackof flexibility and portability, which necessarily limits their useconsiderably.

Description of the invention According to the inventon, a plurality ofcylindrical sections having an equilateral triangular cross-section arerotatably mounted side `by side so that when any one of the threesurfaces of each of the sections are parallel, one surface of eachsection will be juxtaposed to a surface of the adjacent section formingan acoustical wall. One surface of each section is constructed of asoundreflecting material such as tiberboard, a second surface isconstructed of a medium sound absorption material such as acousticaltile, and a third surface can be a lill-in of the cylindrical sectionsof a high absorption of sound material such as fiberglass insulation.Each of the sections are rotatably mounted to a frame and are providedwith a suitable extension or knob on the individual sections forindividual control of each section. The entire unit can `be constructedof a light wood or aluminum for easy portability and, as will be seen,since each section is individually controllable, any desred combinatonof surfaces can be exposed to result in any desired overall acousticalproperty over an extremely Wide range.

An object of the present invention is the provision of an improvedacoustical control device which can variably control the acousdcs of anenvironment over a wide range.

Another object of the invention is the provision of an improvedacoustical control device which is easily transportable.

A further object of the invention is the provision of an improvedacoustical contro-l device which is inexpensive and simple tomanufacture and extremely convenient to set up and adjust.

3,38247 Patented May 14, 1968 Other objects and many of the attendantadvantages of this invention will be readily appreciated as the samebecomes better understood by reference to the following detaileddescription when considered in connection with the accompanying drawingin which like reference numerals designate like parts throughout thefigures thereof and wherein:

FIG. l is a perspective view partially sectioned of the embodiment ofFIG. 1;

FIG. 2 is a view and cross-section taken along lines 2-2 of FIG. l; and

FIG. 3 is a perspective View of the preferred embodiment of the presentinvention.

Operation Referring to FIGS. l and 2, the acoustical control device isshown generally at 11 having a frame comprising `structural members 12,13, 14 and 15. A plurality of triangular sections 16, 17, 18 and 19 aremounted on rods 21 which are rotatably coupled between structuralmembers 12 and 14.

Each triangular section has one surface of a sound refleeting materialsuch as iiberboard 21 indicated as the surface of triangular section 18,and a medium sound absorbing surface such as acoustical tile indicatedat 22 on triangular `section 19. Triangular sections 16 and 17 are shownrotated to an open back position having two surfaces coated with afiberglass insulation 23 which form a relatively high sound absorptionsurface. Alternatively, another structural member could complete thetriangle on each triangular section and that surface coated with a highsound absorption material such as fiberglass insulatron.

Referring to FIG. 3, acoustical cont-rol unit 11 is again shown inperspective from a different angle revealing control knobs 24terminating each rod 21 on the outside of structural member 12.

As can be seen, each of the triangular sections 16, 17, 18 and 19 can beindividually rotated to a desired position exposing one or two of thedifferent surfaces of the section for the desired sound absorption orreflecting quality, depending, of course, upon the acousticalconsiderations of its environment.

lt has been found that one acoustical control unit can be utilized tooptimize the amplitude of sound from a French horn, the bell o-f whichnormally faces to the rear of an orchestra, that is, a direct reflectingsurface would produce too much sound and a high absorption surface, suchas heavy backdrop curtains, tends to absorb too much of the sound,therefor resulting in a `definite need for a reflecting surfacesomewhere in between. It has been found empirically that when all of thetriangular sections are `turned with the high absorption surface 23facing the sound source, the sound source is highly subdued. Utilizingsurface 23, for example, the French horn in a symphony orchestra andother ensembles could easily override the other instruments. Thus, aselection of appropriate surfaces would be made according to the degreeof balance desired under a particular performance condition.

It is contemplated that one or more of these units can be convenientlyplaced in proximity to a sound source for optimizing the acousticalconsiderations with any variety of sound sources. Obviously, theacoustical considerations would differ from a woodwind quintet to a fullsymphony orchestra, or possibly a solo piano accompanist recital, aswell as with the size of the auditorium. These units have also beenfound to be extremely effective in optimizing the acoustics of certainrecording rooms.

It should be understood, of course, that the foregoing disclosurerelates to only a preferred embodiment of the invention, and that it isintended to cover all changes and modifications of the example of theinvention herein chosen, for the purposes of the disclosure, which donot constitute departures from the spirit and scope of the invention. Y

What is lclaimed is: 1. An acoustical control device comprising: aplurality of triangular cylinders having first and second sides forminga V in crosssectiong said cylinders being rotatably mounted in a singlerow; each of said rst sides having an outside surface having a rstacoustical property; each of said second sides having an outside surfacehaving a second acoustical property; and

Cil

each of said rst and second sides having an inside surface having athird acoustical property.

2. The acoustical control device of claim 1 wherein:

each of said cylinders is individually rotatable.

References Cited UNITED STATES PATENTS 1,825,465 9/1931 MacDonalditil-30 3,007,539 11/1961 Brewelet al. L 181-33 I:,Ol9,l2ir0V 8/1962Coffman .181-'33 ROBERT S. WARD, I R., Primary Examiner.

